Continuous blood cell separation and collection is a well-known process for collecting desired blood components, such as red blood cells, platelets or plasma, from a donor. Typically, whole blood is withdrawn from a donor and directed into a centrifugal processing chamber to separate the whole blood into its various therapeutic components. This is usually carried out utilizing blood processing systems and methods comprising a durable centrifuge in association with a single-use, sterile fluid circuit including a processing chamber and associated storage containers, fluid flow tubing, and the like. The processing chamber is usually mounted in a centrifuge rotor or bowl, which spins the chamber, creating a centrifugal field that separates the whole blood into its components based on their density.
A well-known and exemplary centrifugal blood processing system is the Amicus Separator, available from Fenwal, Inc. of Lake Zurich, Ill. The functional aspects of the Amicus Separator are disclosed in, e.g., U.S. Pat. Nos. 6,312,607 and 6,582,349, the entire disclosures of which are incorporated herein by reference.
In centrifugal processing system such as the Amicus, a centrifuge chamber assembly is rotatably mounted to a yoke, and a drive is provided such that the yoke is rotated at a first angular velocity (known in the field as the “one Omega” velocity) and the bowl rotates at a second angular velocity that is twice the first angular velocity (known as the “two Omega” velocity). This relationship of the centrifuge chamber having an angular velocity twice that of the yoke ensures that the bundle of tubings leading to and from the processing chamber that forms a part of the disposable processing fluid circuit (commonly called the “umbilicus”) is not twisted by the rotation of the centrifuge.
In the centrifugal processing systems of the prior art, a first electric motor spins the yoke assembly at one Omega, while a second electric motor mounted to the yoke spins the centrifuge chamber assembly at the same speed of rotation, in the same direction, and about the same axis as the first electric motor spins the yoke assembly. As a result, when viewed from a stationary or non-rotating position, the centrifuge chamber spins at twice the rotational speed of the yoke assembly, thus providing for the one Omega-two Omega relationship between the yoke and centrifuge chamber. Such a drive system is described in U.S. Pat. No. 5,360,542, which is incorporated herein by reference.
By way of the present disclosure, an improved drive system for a centrifuge system is provided that utilizes a single motor to rotate both the yoke and the centrifuge chamber assembly.